1. Field of the Invention
The present invention relates generally to a threaded member capable of detecting tightening force, and more particularly to a threaded member, which has higher strain sensitivity for more precisely detecting the tightening extent of the threaded member.
2. Description of the Related Art
A threaded member is used to tighten a work piece. In engineering, a threaded member is often used to tighten or connect two or more articles with each other. In simple practice, the threaded member is only tightened without noting the tightening torque applied to the threaded member.
However, when the threaded member is applied to a current large-scale building, sophisticated building, sophisticated equipment or highly stressed site, in the case that the threaded member is over-tightened or under-tightened, the structural strength of the building and the operation effect of the mechanical equipment will be affected. This will even threaten the security of lives and properties of users. Therefore, when tightened, the tightening extent of the threaded member must be monitored, measured and recorded so as to ensure safety.
In order to achieve the above object, the applicant's Taiwan Patent No. I310810 discloses an engineering threaded member capable of showing torque value as shown in FIGS. 1 and 2. The threaded member includes a threaded member A10 and a torque measuring unit A20. The threaded member A10 has a head section A11 and a threaded rod section A12. The torque measuring unit A20 is disposed on the head section A11, having a processing/display unit A21 and a sensor A22 for detecting the deformation of the head section A11. When the threaded member A10 is tightened, the sensor A22 detects the deformation of the head section and transmits a signal to the processing/display unit A21 to display the tightening force applied to the threaded member A10.
The above patent enables a user to read the tightening extent of the threaded member. However, the sensitivity of the threaded member is insufficient. This is because when the threaded member A10 is tightened with a locked article as shown in FIG. 2, the head section A11 is in contact with the locked article. The head section A11 of the threaded member is a solid body so that the deformation of the head section is small. The sensor A22 can detect the deformation and find the tightening torque only when the head section is deformed to a certain extent. Therefore, the conventional threaded member A10 can hardly sensitively and precisely detect the deformation extent so that it is hard for a user to read a precise tightening torque.
It is therefore tried by the applicant to further provide a threaded member capable of detecting tightening force, which has higher strain sensitivity for more precisely detecting the tightening torque of the threaded member so as to ensure safety.